Prospective longitudinal assessment of parotid gland function using dynamic quantitative pertechnate scintigraphy and estimation of dose–response relationship of parotid-sparing radiotherapy in head-neck cancers

Gupta, Tejpal; Hotwani, C.; Kannan, Sadhana; Master, Zubin; Rangarajan, Venkatesh; Murthy, Vedang; Budrukkar, Ashwini; Ghosh‐Laskar, Sarbani; Agarwal, Jai Prakash

doi:10.1186/s13014-015-0371-2

Cited by 27 publications

(29 citation statements)

References 37 publications

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“…This allows for an increased dose to the tumor at a reduced integral dose to the normal tissue and organs at risk (OAR) with respect to conventional photon therapy. Two of the indications potentially benefiting from the more conformal dose distributions in IMPT are tumors in the head and neck (H&N) region, [3][4][5] as well as tumors of the prostate. [6][7][8] However, enhanced conformity comes along with an increased sensitivity to anatomical variations during the course of fractionated treatment.…”

Section: Introductionmentioning

confidence: 99%

Investigating deformable image registration and scatter correction for CBCT‐based dose calculation in adaptive IMPT

et al. 2016

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International audiencePurpose:This work aims at investigating intensity corrected cone-beam x-ray computed tomography (CBCT) images for accurate dose calculation in adaptive intensity modulated proton therapy (IMPT) for prostate and head and neck (H&N) cancer. A deformable image registration (DIR)-based method and a scatter correction approach using the image data obtained from DIR as prior are characterized and compared on the basis of the same clinical patient cohort for the first time.Methods:Planning CT (pCT) and daily CBCT data (reconstructed images and measured projections) of four H&N and four prostate cancer patients have been considered in this study. A previously validated Morphons algorithm was used for DIR of the planning CT to the current CBCT image, yielding a so-called virtual CT (vCT). For the first time, this approach was translated from H&N to prostate cancer cases in the scope of proton therapy. The warped pCT images were also used as prior for scatter correction of the CBCT projections for both tumor sites. Single field uniform dose and IMPT (only for H&N cases) treatment plans have been generated with a research version of a commercial planning system. Dose calculations on vCT and scatter corrected CBCT (CBCT cor) were compared by means of the proton range and a gamma-index analysis. For the H&N cases, an additional diagnostic replanning CT (rpCT) acquired within three days of the CBCT served as additional reference. For the prostate patients, a comprehensive contour comparison of CBCT and vCT, using a trained physician’s delineation, was performed.Results:A high agreement of vCT and CBCT cor was found in terms of the proton range and gamma-index analysis. For all patients and indications between 95% and 100% of the proton dose profiles in beam’s eye view showed a range agreement of better than 3 mm. The pass rate in a (2%,2 mm) gamma-comparison was between 96% and 100%. For H&N patients, an equivalent agreement of vCT and CBCT cor to the reference rpCT was observed. However, for the prostate cases, an insufficient accuracy of the vCT contours retrieved from DIR was found, while the CBCT cor contours showed very high agreement to the contours delineated on the raw CBCT.Conclusions:For H&N patients, no considerable differences of vCT and CBCT cor were found. For prostate cases, despite the high dosimetric agreement, the DIR yields incorrect contours, probably due to the more pronounced anatomical changes in the abdomen and the reduced soft-tissue contrast in the CBCT. Using the vCT as prior, these inaccuracies can be overcome and images suitable for accurate delineation and dose calculation in CBCT-based adaptive IMPT can be retrieved from scatter correction of the CBCT projections

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Section: Introductionmentioning

confidence: 99%

Investigating deformable image registration and scatter correction for CBCT‐based dose calculation in adaptive IMPT

et al. 2016

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“…On the contrary, the radioactivity found in the glands originates from the saliva rather than from the parotid parenchyma. Nevertheless, our study provides a temporal resolution (4 s per scan) much better than that (16–120 s per scan) used in scintigraphy . This means that our study might allow more accurate quantification of both amplitude and time‐related semi‐quantitative parameters than current scintigraphic studies.…”

Section: Discussionmentioning

confidence: 95%

Proton change of parotid glands after gustatory stimulation examined by magnetic resonance imaging

et al. 2018

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The aim of this study was to investigate proton changes of the parotid gland after gustatory stimulation by semi-quantitative parameters and an empirical mathematical model (EMM) using high-temporal-resolution, double-echo, echo-planar imaging (EPI). Approved by a local institutional review board, this study examined 20 parotid glands from 10 healthy volunteers (male:female = 6: 4; age ± standard deviation =35.1 ± 14.1 years) with written informed consent obtained. All participants underwent 1.5-T, double-echo EPI with gustatory stimulation. Semi-quantitative parameters, including maximal drop ratio (MDR), time to peak (TTP), drop slope (DS), recovery slope (RS) and recovery ratio (RR), were calculated. The effect of temporal resolution on parotid functional parameters was evaluated. An EMM comprising an output function ( Sot=Aoe-kot+B) and an input function ( Sint=Ain1-e-kint) was also applied to fit all dynamic curves. Kruskal-Wallis test, Wilcoxon test, linear regression analysis and goodness of fit were used for statistical analysis. p < 0.05 was considered to be statistically significant. The signal intensity dropped significantly after gustatory stimulation on the proton density (PD) image (p < 0.01). MDR was 8.26% in the PD image. MDR and RR were negatively associated with time interval, whereas DS and TTP were significantly positively associated with time interval (all p < 0.05). EMM parametric values derived from PD-time curves of parotid glands were 12.04 ± 6.81%, 6.43 ± 4.23 min , 88.73 ± 6.18%, 8.41 ± 4.86 min and 1.09 ± 1.35 for A , k , B, A and k , respectively. Semi-quantitative functional parameters and EMM parameters using high-temporal-resolution, double-echo EPI allow the quantification of parotid proton changes after gustatory stimulation.

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“…Design and eligibility: Trial design, eligibility, and conduct have been described in detail previously (11,15). Brie y, biopsy-proven and previously untreated patients with early to moderately advanced nonmetastatic squamous carcinoma of the oropharynx, larynx (excluding T1 glottic cancer), or hypopharynx (T1-T3, N0-N2b, M0) as per Tumor-Node-Metastases (TNM) classi cation of the 7 th edition of American Joint Committee on Cancer (AJCC) staging requiring comprehensive irradiation of primary tumor and bilateral neck nodes were included.…”

Section: Methodsmentioning

confidence: 99%

“…It is widely accepted that salivary gland function starts recovering 3-6 months after RT and gradually improves over time (3,6,7); hence, whether the difference in IMRT versus conventional 2D-RT/3D-CRT persists at a longer follow-up beyond 5-years is largely unknown. We had earlier reported the safety and e cacy outcomes (11) as well as dose-response relationship of the parotid glands (15) from our randomized trial comparing IMRT with 3D-RT in the curative-intent radiotherapeutic management of non-nasopharyngeal HNSCC in the de nitive setting. Herein, we report and compare the long-term disease-related outcomes and late toxicity of the index trial at an extended and mature followup (>10 years).…”

Section: Introductionmentioning

confidence: 99%

Intensity-modulated radiation therapy versus three-dimensional conformal radiotherapy in head and neck squamous cell carcinoma: long-term and mature outcomes of a prospective randomized trial

Gupta

Sinha

Laskar

et al. 2020

Preprint

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Purpose: To compare long-term disease-related outcomes and late radiation morbidity between intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) in head and neck squamous cell carcinoma (HNSCC) in the setting of a prospective randomized controlled trial.Methods: Previously untreated patients with early to moderately advanced non-metastatic squamous carcinoma of the oropharynx, larynx, or hypopharynx (T1-T3, N0-N2b, M0) planned for comprehensive irradiation of primary site and bilateral neck nodes were randomly assigned to either IMRT or 3D-CRT after written informed consent. Patients were treated with 6MV photons to a total dose of 70Gy/35 fractions over 7 weeks (3D-CRT) or 66Gy/30 fractions over 6 weeks (IMRT). A sample size of 60 patients was estimated to demonstrate 35% absolute difference in the incidence of ≥grade 2 acute xerostomia between the two arms. All time-to-event outcomes were calculated from date of randomization until the defined event using the Kaplan-Meier method. Results: At a median follow-up of 140 months for surviving patients, 10-year Kaplan-Meier estimates of loco-regional control (LRC); progression-free survival (PFS); and overall survival (OS) with 95% confidence interval (95%CI) were 73.6% (95%CI: 61.2-86%); 45.2% (95%CI: 32-58.4%); and 50.3% (95%CI: 37.1-63.5%) respectively. There were no significant differences in 10-year disease-related outcomes between 3D-CRT and IMRT for LRC [79.2% (95%CI: 62.2-96.2%) vs 68.7% (95%CI: 51.1-86.3%), p=0.39]; PFS [41.3% (95%CI: 22.3-60.3%) vs 48.6% (95%CI: 30.6-66.6%), p=0.59]; or OS [44.9% (95%CI: 25.7-64.1%) vs 55.0% (95%CI: 37-73%), p=0.49]. Significantly lesser proportion of patients in the IMRT arm experienced ≥grade 2 late xerostomia and subcutaneous fibrosis at all time-points. However, at longer follow-up, fewer patients remained evaluable for late radiation toxicity reducing statistical power and precision. Conclusions: IMRT provides a clinically meaningful and sustained reduction in the incidence of moderate to severe xerostomia and subcutaneous fibrosis compared to 3D-CRT without compromising disease-related outcomes in long-term survivors of non-nasopharyngeal HNSCC.

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Prospective longitudinal assessment of parotid gland function using dynamic quantitative pertechnate scintigraphy and estimation of dose–response relationship of parotid-sparing radiotherapy in head-neck cancers

Cited by 27 publications

References 37 publications

Investigating deformable image registration and scatter correction for CBCT‐based dose calculation in adaptive IMPT

Investigating deformable image registration and scatter correction for CBCT‐based dose calculation in adaptive IMPT

Proton change of parotid glands after gustatory stimulation examined by magnetic resonance imaging

Intensity-modulated radiation therapy versus three-dimensional conformal radiotherapy in head and neck squamous cell carcinoma: long-term and mature outcomes of a prospective randomized trial

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